The present invention generally relates to a vibration dampening device or capo that can be deployed to damp the strings of a stringed instrument such as a guitar, banjo, or dulcimer, and is especially of value in connection with damping the strings of a stringed instrument comprising a fretted fingerboard; the fingerboard of such instrument is outfitted with a plurality of frets at selected spacings from one another along the fingerboard's length. A vibration dampening device can simultaneously alter the pitch of the entirety of strings along the musical scale or, alternatively, can be configured to only alter the pitch of selected ones of the strings. String instruments create different tones by varying the string thickness, tension and length. On a given instrument, the player may vary the tone on a selected string by pressing the string against a support base (like a fret board on a guitar) and by that action can shorten the length of the string and also change the tone. On some string instruments, a capo is used to create a temporary shortening of all strings to simplify playing in certain keys.
One type of capo—i.e., a vibration dampening device for stringed instruments—has been available commercially and comprises a pressure bar and a neck engaging jaw. The pressure bar of the vibration dampening device is moved into contact with the top of the strings along the fingerboard of the stringed instrument at a location between two successive frets. A clamping force which can optionally be provided as a variable clamping force is applied via a movement of the pressure bar and the neck engaging jaw toward one another and the clamping force is selected or calibrated to cause the pressure bar to press the instrument's strings down against the fingerboard or to press the instrument's strings downwardly toward the fingerboard to an extent that unwanted vibration or “buzzing” of the strings is foreclosed. The instrument's strings are thus downwardly depressed in the extent between the two respective successive frets. One known drawback of a vibration dampening device operated in this manner is that downward displacement of the strings between the two respective successive frets may lead to the stringed instrument being disposed into an “out of tune” condition, due to excessive force, during the clamping operation of the vibration dampening device. This necessitates restoring the instrument to its appropriate tune after installation of the vibration dampening device—that is, the pitch of the strings needs to be adjusted—so that the pitch of the strings is suitable to the user of the stringed instrument.
While the reliability and convenience of a vibration dampening devices for use with stringed musical instruments have been demonstrated, there still remains a need for a vibration dampening devices for use with stringed musical instruments that provides even greater convenience to a user and that reduces the risk that an excessive force will be applied to the stringed instrument.